Underground utility boxes are used to provide access to a variety of different underground systems, such as electric, gas, water, telephone, data, and so forth. For example, a utility box can provide access to a valve, meter, or utility junction that is disposed under the ground. These boxes are typically comprised of a housing that fits over the portion of the system to which access is desired. The housing fits down into the ground, and is designed to be substantially completely buried, with the top of the housing disposed at about ground level. The housing is constructed in such a manner that it is difficult to remove the housing, without removing the earth around the box.
Utility boxes of this type typically have a cover that protects the system that is exposed within the box from unauthorized access or consequential damage. The cover is usually fastened to the box with one or more bolts that pass through the cover and are retained by some type of connection to the housing. Because the utility box cannot be conveniently accessed from below, the connection needs to be retained in some manner in the housing, so that the bolt can thread to it.
To accomplish this, underground utility box manufacturers fabricate their boxes with nuts that are affixed in some manner to the housing against which the cover is fastened. The nuts can be glued to the housing with an adhesive, or can be molded directly into the material of which the housing is formed. In this manner, the cover can be placed on the housing, and the bolt can be inserted through the holes in the cover and threaded into the nut that is affixed to the housing.
Unfortunately, the nuts tend to work loose from the housing over time. This can happen just through normal use over an extended period of time, or it can happen immediately if the bolt is tightened onto the nut with too great a force. Another problem with this configuration is when the nut becomes damaged in some manner. For example, if the bolt is not inserted correctly into the nut, the nut can be cross threaded. When problems such as any of these occur, there is no easy way to replace the nut in the housing, and in many cases the housing has to be damaged in order to remove and replace the nut.
In an effort to provide a field replaceable nut, some manufacturers have introduced additional flaws to their products. In some cases, the nut is inserted into the ring with no means of drainage beneath the nut. Since the product is typically used outside and exposed to the elements, water inevitably enters the fastener and settles in the area of the nut. Two problems can result from this scenario. First, the fastener and nut are subjected to the corrosive effects of the trapped water, and second, when the product is exposed to freezing temperatures, the water expands and cracks the ring.
In other cases, nuts require replacement due to damage from weather or other causes. Typically, only specific sizes of nuts are available for securing the cover because of constraints in the design of the ring.
What is needed, therefore, is a system that overcomes problems such as those described above, at least in part.